The present invention relates to an aircraft nacelle comprising two fan cowl doors which are mounted rotatably about an axis parallel to the longitudinal axis of the nacelle, and to an aircraft comprising at least one such nacelle.
An aircraft comprises at least one nacelle which houses an engine, for example of the jet engine type, and which is suspended from a pylon attached beneath a wing of the aircraft.
Conventionally, a nacelle for a jet engine is structured with three functional zones: the air intake zone at the front, in the upstream direction of the aerodynamic flow; the zone of the fan cowl doors in the central portion, which cover the casing of the fan of the engine; and the thrust-reversal system zone, which covers the turbine unit of the jet engine at the rear, in the downstream direction of the aerodynamic flow. The zone of the fan cowl doors of the nacelle comprises two fan cowl doors which are arranged on either side of the pylon and which may be opened in order to carry out maintenance on the engine.
Each fan cowl door is articulated on hinges about an opening axis parallel to the longitudinal axis of the nacelle and arranged in the upper portion of the fan cowl door.
Thus, each fan cowl door is able to move between a closed position in which the fan cowl door is arranged in line with the outer surface of the nacelle so as to cover the fan casing, and an open position in which an operative has access to the engine.
The lower edges of the fan cowl doors, which are located in the lower portion of the nacelle, are essentially touching in the closed position and are held in this closed position by a locking system which holds the two fan cowl doors together.
Currently, nacelles are increasing in size, which also implies an increase in the size of these fan cowl doors. However, when the fan cowl doors are in the open position, it is necessary to keep a safe distance between the fan cowl doors and the surface of the wing beneath which the nacelle is installed. Keeping this safe distance means that the opening of the fan cowl doors is limited, which reduces accessibility for the operative.
In addition, the increasing diameter of the nacelles tends to reduce the clearance between the bottom of the nacelles and the ground. This makes access to the fan cowl door locking system difficult for the operatives.
Furthermore, the increased size of the fan cowl doors has consequences for their manufacturing tolerances, deformation in flight, or the need to strengthen the hinges.